Australasian Society for HIV Medicine

A review of the fusion inhibitor enfuvirtide, by Mark Boyd and Sarah Pett, is reported in the June issue of Australian Prescriber. HIV fusion inhibitors represent a novel class of antiretroviral drugs and enfuvirtide was the first drug within this class to be approved for use in Australia.(1)

Enfuvirtide, developed by the pharmaceutical company Trimeris in 1996, was initially designated T-20. In 1999, Trimeris entered into partnership with Hoffmann-La Roche to complete the development of the drug. Approved by the U.S. Food and Drug Administration (FDA) in 2003, Enfuvirtide was the first in class HIV fusion inhibitor. It was approved on the basis of two studies, TORO 1 and TORO 2 which compared the effect of optimised regimens of antiretroviral medication with and without the addition of enfuvirtide on viral load.

Enfuvirtide is a synthetic 36-amino acid peptide analogue. It binds to the first heptad repeat region of gp41, disrupting interactions with the second heptad repeat region of gp41, thereby interrupting the fusion reaction and preventing the virus from infecting the host cell. While the use of enfuvirtide is associated with substantial improvements in virological, immunological and clinical outcomes in treatment-experienced patients, particularly when combined with antiretroviral drugs, its uptake has been limited because of the need for delivery by twice-daily subcutaneous injection. However, there is no doubt that the drug offers potent antiretroviral activity, and its use should be strongly considered in patients with multiple regimen failures as a component of a new regimen aimed to effect full and durable virological suppression.(1)

Next-generation fusion inhibitors, including TRI-1144, and the new class of HIV entry inhibitors, the chemokine (C-C motif) receptor 5 (CCR5) antagonists are also discussed in the review.

HIV s100 prescribers are invited to review this article in the current issue of the Australian Prescriber. Prescribers (and any other registered medical practitioners) may register with this publication for hard copies via the website.

Authors Affiliation: Mark Boyd and Sarah Pett, Infectious Diseases Physicians, Therapeutic and Vaccine Research Program, National Centre in HIV Epidemiology and Clinical Research, University of New South Wales, and the HIV, Immunology and Infectious Diseases Clinic Services Unit, St Vincent's Hospital, Sydney.

Reference

(1) Boyd M and Pett SHIV fusion inhibitors: a review Aust Prescr 2008;31:66-9
Link to review: http://www.australianprescriber.com/upload/pdf/articles/958.pdf

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